Is diabetes hereditary?
You have diabetes, and one of your parents/grandparents/great grandparents etc. also had/have it. Diabetes is hereditary, but you can still reduce the risk of your children developing it.
Are all types of diabetes hereditary?
Yes, but the hereditary factor (genetic transmission) is different depending on the type of diabetes.
It seems that type 1 diabetes has much less risk of being genetically transmitted than type 2 diabetes.
Type 2 diabetes, also known as "adult-onset diabetes" or non-insulin-dependent diabetes, is the kind most commonly found in families.
35% of people with a direct relative (father, mother, brother or sister) who has type 2 diabetes will be diabetic.
How is diabetes transmitted?
As far as we currently know, no one gene is responsible for transmitting type 2 diabetes.
Its transmission is believed to be caused by a combination of several factors:
- The combination of several predisposing genes
- An unsuitable diet
- Not enough or no physical exercise.
However, a small number of type 2 diabetes cases, known as MODY (maturity onset diabetes of the young) and which begin before the age of 30, are linked to the transmission of one faulty gene. In this case, the risk of genetic transmission is higher, at around 50%.
I'm pregnant. Will I transmit diabetes to my child?
Being diabetic during pregnancy does not increase the risk of transmitting diabetes to the baby when it is born. This is true in all cases, whether you are diabetic prior to becoming pregnant or develop diabetes during pregnancy (gestational diabetes).
However, it is important to closely monitor your blood sugar and achieve the correct balance, from the preconception period (when you stop using contraception) onwards. This is to reduce the risk of deformities in the baby, achieve a good blood sugar balance during pregnancy and avoid problems during the birth.
What can I do to reduce the risks?
If you have type 2 diabetes and are concerned for your children, the first steps to take are as follows:
Changes your make to your own diet and lifestyle will become the habits that your child will learn and maintain.
Above all, you should avoid weight gain. The risks of insulin resistance, and therefore diabetes, are higher in people who are overweight.
What is a balanced diet?
Briefly, a balanced diet involves:
- Spreading meals out throughout the day
- Learning what your meals should contain
- Varying your diet in order to keep the body functioning correctly.
Balanced calorie intake is essential, i.e. a sufficient quantity to provide strength distributed between the different nutrients the body needs each day:
- Carbohydrates (simple and complex sugars)
- Lipids (fats)
- Proteins (animal- or plant-derived amino acids).
Excessive variations in intake or an imbalance between activities and the quantity of food can cause metabolic problems.
In order to reduce the risk of diabetes in a child who has at least one parent with type 2 diabetes, it is essential to introduce and follow certain lifestyle and diet rules as a family. These should include a balanced diet and regular physical exercise. If the child adopts good habits, the risk of diabetes will be reduced or delayed.
Updated September 2011
Dr Stephen MulveyGeneral Practice
The Home edition of The Merck Manual of Medical Information is based on the world's most widely used textbook of medicine, but written in everyday language by around 300 outstanding contributors.
The book covers many difficult medical concepts, but is written in everyday language.
Merck Manual Home Edition